This invention relates to a process for recovering at least one metal, e.g., gold, silver, the platinum group metals and the like, from an ore containing carbonaceous material and the metal to be recovered. In particular, the invention relates to a process which involves processing a metal-containing ore so as to facilitate the recovery of the metal from the ore.
Carbonaceous ores, i.e., ores which contain elemental carbon (e.g., graphite) and/or organic compounds, often contain valuable metals, such as gold, silver, the platinum group metals and the like. One characteristic of such ores which has made them difficult and expensive to process is that the presence of carbon and organic compounds inhibits metal recovery using conventional, e.g., cyanide, processing. In other words, the presence of organic material in such carbonaceous ores tends to interfere with metal extraction, e.g., by cyanidation. For example, a substantial amount of carbonaceous ore is not amenable to conventional cyanidation techniques because of the presence of carbon (which often acts like activated carbon), and relatively long chained organic hydrocarbon-type compounds containing sulfur, nitrogen, carboxylic acid groups and the like.
There is a growing world-wide interest in metal recovery from carbonaceous ores. Thus, in spite of the substantial work which has been done to provide for such metal recovery, a need currently exists to provide for a process for metal recovery from carbonaceous ores.